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Proceedings of the American Mathematical Society

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Is there a point of $ \omega\sp *$ that sees all others?

Author: Neil Hindman
Journal: Proc. Amer. Math. Soc. 104 (1988), 1235-1238
MSC: Primary 04A20; Secondary 03E05, 54D35
MathSciNet review: 931732
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Abstract: If the cardinal $ c$ of the continuum is singular and $ p$ is an ultrafilter on $ \omega $ of character $ c$, then there is an ultrafilter $ q$ on $ \omega $ which is not comparable to $ p$ in the Rudin-Keisler order.

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Keywords: Ultrafilters, Rudin-Keisler order
Article copyright: © Copyright 1988 American Mathematical Society

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